Apparatus, system, and method for minimized energy in peripheral field stimulation

ABSTRACT

In various examples, an apparatus is configured for at least partial insertion in a living body. The apparatus includes an elongate lead body including a proximal lead end and a distal lead end. At least one connector is disposed proximate the proximal lead end. At least one flexible conductive surface is disposed at least partially around the lead body proximate the distal lead end. At least one conductor extends within the lead body from the at least one connector to the at least one flexible conductive surface.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. Provisional Application Ser. No. 61/841,965, filed on Jul. 2, 2013, entitled “STIMULATION APPARATUSES, DEVICES, SYSTEMS, AND METHODS,” which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present patent document pertains generally to peripheral field stimulation and more particularly, but not by way of limitation, to an implantable peripheral field stimulation apparatus, system, and method.

BACKGROUND

Peripheral nerve field stimulation (PNFS), where multicontact percutaneous leads are positioned underneath the skin, recruits nerve fiber endings and axons in the cutaneous and subcutaneous layers, usually within a few centimeters of the electrodes. Traditional lead designs for spinal cord stimulation (SCS) are often used for PNFS. While these can provide adequate coverage, SCS systems have certain challenges when used in PNFS applications.

OVERVIEW

This overview is intended to provide an overview of subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the present patent application.

The present inventor has recognized, among other things, that the subject matter can be used for stimulation of peripheral nerves. Peripheral nerves can be defined as branches of peripheral nerves, groups of peripheral nerves, and/or larger areas of individual nerves. The present inventor has further recognized, among other things, that the subject matter can be used for implantable peripheral nerve stimulation. To better illustrate the apparatuses, systems, and methods described herein, a non-limiting list of examples is provided here:

Example 1 can include subject matter that can include an apparatus configured for at least partial insertion in a living body. The apparatus includes an elongate lead body including a proximal lead end and a distal lead end. At least one connector is disposed proximate the proximal lead end. At least one flexible conductive surface is disposed at least partially around the lead body proximate the distal lead end. At least one conductor extends within the lead body from the at least one connector to the at least one flexible conductive surface.

In Example 2, the subject matter of Example 1 is optionally configured such that the at least one flexible conductive surface includes a mesh.

In Example 3, the subject matter of any one of Examples 1-2 is optionally configured such that the at least one flexible conductive surface includes a coil.

In Example 4, the subject matter of any one of Examples 1-3 is optionally configured such that the at least one flexible conductive surface is disposed completely around the lead body.

In Example 5, the subject matter of any one of Examples 1-4 is optionally configured such that the at least one flexible conductive surface includes a length between 1 cm and 20 cm.

In Example 6, the subject matter of any one of Examples 1-5 is optionally configured such that the at least one flexible conductive surface includes two or more flexible conductive surfaces.

In Example 7, the subject matter of Example 6 is optionally configured such that the two or more flexible conductive surfaces includes at least three flexible conductive surfaces, wherein a center flexible conductive surface includes a first length; a distal flexible conductive surface disposed distally on the elongate lead body from the center flexible conductive surface and including a second length; and a proximal flexible conductive surface disposed proximally on the elongate lead body from the center flexible conductive surface and including a third length. The second and third lengths are shorter than the first length.

In Example 8, the subject matter of Example 7 is optionally configured such that the at least three flexible conductive surfaces are longitudinally spaced along the elongate lead body from one another.

In Example 9, the subject matter of any one of Examples 7-8 is optionally configured such that the second length is substantially equal to the third length.

In Example 10, the subject matter of any one of Examples 7-9 is optionally configured such that the first length is 12-16 mm and the second length and the third length are each 7-11 mm.

In Example 11, the subject matter of any one of Examples 1-10 is optionally configured such that the at least one conductor extends within a lumen of the lead body.

In Example 12, the subject matter of any one of Examples 1-11 is optionally configured such that the at least one conductor includes two or more conductors, wherein one of the conductors is disposed within a first lumen of the lead body and another of the conductors is disposed within a second lumen of the lead body.

In Example 13, the subject matter of Example 12 is optionally configured such that the lead body includes a stylet lumen configured to accept a stylet within the stylet lumen.

Example 14 can include, or can optionally be combined with any one of Examples 1-13 to include subject matter that can include an apparatus configured for at least partial insertion in a living body. The apparatus includes an elongate lead body including a proximal lead end, a distal lead end, and a lumen within the lead body. A connector is disposed proximate the proximal lead end. A flexible conductive surface is disposed at least partially around the lead body proximate the distal lead end. A conductor extends within the lumen, the conductor extending from the connector to the flexible conductive surface.

In Example 15, the subject matter of Example 14 is optionally configured such that the flexible conductive surface includes a mesh.

In Example 16, the subject matter of any one of Examples 14-15 is optionally configured such that the flexible conductive surface includes a coil.

In Example 17, the subject matter of any one of Examples 14-16 optionally includes at least a second flexible conductive surface disposed at least partially around the lead body proximate the distal lead end.

Example 18 can include, or can optionally be combined with any one of Examples 1-17 to include subject matter that can include an apparatus configured for at least partial insertion in a living body. The apparatus includes an elongate lead body including a proximal lead end, a distal lead end, and at least one lumen within the lead body. At least one connector is disposed proximate the proximal lead end. At least one flexible conductive surface is disposed around the lead body proximate the distal lead end. At least one conductor extends within the at least one lumen, the at least one conductor extending from the at least one connector to the at least one flexible conductive surface. A stylet lumen is disposed within the lead body, the stylet lumen being configured to accept a stylet within the stylet lumen.

In Example 19, the subject matter of Example 18 is optionally configured such that the flexible conductive surface includes a mesh.

In Example 20, the subject matter of any one of Examples 18-19 is optionally configured such that the flexible conductive surface includes a coil.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an apparatus including a flexible conductive surface in accordance with at least one example of the invention.

FIG. 2 shows an apparatus including a flexible conductive surface in accordance with at least one example of the invention.

FIG. 3 shows an apparatus including a flexible conductive surface in accordance with at least one example of the invention.

FIG. 4 shows a graph including data related to potential at various distances from an apparatus in accordance with at least one example of the invention.

FIG. 5 shows a graph including data related to potential at various distances from a spinal cord stimulation lead.

FIG. 6 shows an apparatus including a flexible conductive surface in accordance with at least one example of the invention.

FIG. 7 depicts current density profiles of apparatuses including flexible conductive surfaces in accordance with examples of the invention.

FIG. 8 shows an example of an apparatus in accordance with at least one example of the invention, the apparatus including multiple lumens.

FIGS. 9A-9C show example configurations of apparatuses in accordance with examples of the invention.

DETAILED DESCRIPTION

The present patent document relates to apparatuses, systems, and methods for peripheral field stimulation. For instance, the apparatuses, systems, and methods of the present patent document are used, in some examples, to provide peripheral nerve field stimulation (PNFS) to extremities or other body segments. The present patent document relates to, among other things, stimulation of peripheral nerves. Peripheral nerves can be defined as branches of peripheral nerves, groups of peripheral nerves, and/or larger areas of individual nerves.

The present inventor has recognized, among other things, that it is desirable to have PNFS apparatuses, systems, and methods which include one or more flexible conductive surfaces. The present inventor has further recognized, among other things, that it is desirable to have PNFS apparatuses, systems, and methods configured to generate a broad field. The present inventor has further recognized, among other things, that it is desirable to have PNFS apparatuses, systems, and methods configured for placement in patient extremities or other body segments. It should be understood, however, that the subject matter described herein can be used with other implantable medical devices, as well as an external device in some examples.

Spinal cord stimulation (SCS) systems have certain challenges when used in PNFS applications. One challenge is that SCS lead contacts are usually only about 3 mm in length. This length was chosen for SCS as a good compromise between DC fiber selectivity, moderate impedance, enough focal current density, and ease of manufacturability. However, selectivity and focal current density are relatively unimportant in PNFS, as the stimulation goal is to generate as broad a field as is comfortably possible. Most SCS leads cover no more than 6 cm, and they do this by using contacts that are separated by several millimeters of insulator. Even when these leads are programmed with all the same polarity, the field near the contacts still undulates in space and this can promote activation of fibers near the contacts rather than further away. And, the moderate impedance that results from small SCS contacts is likely too high for PNFS.

Additionally, the contacts are typically rigid metallic cylinders, which can be useful in SCS to provide mechanical stability for lead positioning within the bony canal of the spine, as well as for a robust substrate for current/voltage delivery. In PNFS, however, electrode contact length and rigidity can make them difficult to position over curved body regions such as a leg or a skull, or around bony structures, and may promote skin erosion or lead breakage over time.

Finally, PNFS has been employed primarily in the trunk to treat overall back pain and this has been reasonably successful. What has not been addressed is that patients often have focal pain in extremities that would better benefit by deployment of PNFS stimulation in those regions. In addition, the power requirements of PNFS are similar to SCS, so the use of traditional SCS systems in extremity PNFS is challenged from both a stimulator size and power problem, i.e., the batteries have to be large enough to support the required stimulation power, yet such sizes cannot be implanted on the extremities because of anatomic, cosmesis, and comfort concerns.

What is needed includes stimulation systems, apparatuses, and methods that can provide PNFS to extremities using a stimulation system designed to meet the requirements of PNFS. To that end, and with reference to FIGS. 1-9C, various examples are contemplated herein. In some embodiments, long flexible grossly-cylindrical conductive surfaces act as stimulation electrodes and are deployed along a flexible lead for subcutaneous placement and stimulation of surrounding tissue. In some embodiments, the distribution of different lengths of flexible conductors is provided in a manner intended to equalize the relative current passing through each conductive surface to the tissue. In some embodiments, the present systems, apparatuses, and methods allow for the connection of one or more stimulating leads to a microstimulator deployable on the same body segment as the connected leads is provided.

Referring to FIG. 1, an apparatus 100 is configured for at least partial insertion in a living body. In some examples, the apparatus 100 is a stimulation lead for selective attachment to a stimulation device, such as, for instance, a microstimulator. Although described primarily herein with respect to stimulation leads, it should be understood that, in other examples, the apparatus can include other at least partially implantable devices.

In some examples, the apparatus 100 includes an elongate lead body 102 including a proximal lead end 102A and a distal lead end 102B. In some examples, at least one connector 104 is disposed proximate the proximal lead end 102A. In some examples, the at least one connector 104 is configured to electrically couple to the stimulation device. In some examples, at least one flexible conductive surface 110 is disposed at least partially around the lead body 102 proximate the distal lead end 102B. In some examples, the at least one flexible conductive surface 110 is disposed completely around the lead body 102. The apparatus 100 further includes, in some examples, at least one conductor 106 extending within the lead body 102 from the at least one connector 104 to the at least one flexible conductive surface 110. In some examples, the at least one conductor 106 extends within a lumen 103 of the lead body 102.

In some examples, the apparatus 100 includes one flexible conductor 110. In other examples, the apparatus 100 includes two or more flexible conductive surfaces 110 separated by a distance. In some examples, the apparatus 100 includes a plurality of flexible conductive surfaces 110. In the example shown in FIG. 1, the apparatus 100 includes seven flexible conductive surfaces 110. In other examples, the apparatus 100 can include more or fewer than seven flexible conductive surfaces 110. In some examples, each of the flexible conductive surfaces 110 is substantially the same length. In other examples, the flexible conductive surfaces 110 include different lengths. In some examples, the flexible conductive surfaces 110 are longitudinally spaced along the lead body 102. In some examples, spacing between each of the flexible conductive surfaces 110 is substantially similar. In other examples, spacing between each of the flexible conductive surfaces 110 varies.

In some examples, the at least one flexible conductive surface 110 includes a mesh. In some examples, the at least one flexible conductive surface 110 is made of a metal mesh that envelopes the circumference of the lead body 102. In some embodiments, the mesh of the at least one flexible conductive surface 110 can include a ‘rough’ surface that increases the geometric surface area of the at least one flexible conductive surface 110. In some instances, this increased geometric surface area can reduce the resistance while increasing the reactance of the effective electrode of the at least one flexible conductive surface 110. By doing so, in some examples, the voltage to generate a specific current is reduced throughout the stimulation portion of the waveform, which can save battery power. In some examples, the mesh can include an arrangement of single cross-hatched, braided, or otherwise disposed or applied conductors; an arrangement of multistranded cross-hatched, braided, or otherwise disposed or applied conductors, and/or a variety of deposited thin film conductive elements, to name a few.

Referring to FIG. 2, an apparatus 200 is configured for at least partial insertion in a living body. In some examples, the apparatus 200 is a stimulation lead for selective attachment to a stimulation device, such as, for instance, a microstimulator. Although described primarily herein with respect to stimulation leads, it should be understood that, in other examples, the apparatus can include other at least partially implantable devices.

In some examples, the apparatus 200 includes an elongate lead body 202 including a proximal lead end 202A and a distal lead end 202B. In some examples, at least one connector 204 is disposed proximate the proximal lead end 202A. In some examples, the at least one connector 204 is configured to electrically couple to the stimulation device. In some examples, at least one flexible conductive surface 210 is disposed at least partially around the lead body 202 proximate the distal lead end 202B. In some examples, the at least one flexible conductive surface 210 is disposed completely around the lead body 202. The apparatus 200 further includes, in some examples, at least one conductor 206 extending within the lead body 202 from the at least one connector 204 to the at least one flexible conductive surface 210. In some examples, the at least one conductor 206 extends within a lumen 203 of the lead body 202.

In some examples, the apparatus 200 includes one flexible conductor 210. In other examples, the apparatus 200 includes two or more flexible conductive surfaces 210 separated by a distance. In some examples, the apparatus 200 includes a plurality of flexible conductive surfaces 210. In the example shown in FIG. 2, the apparatus 200 includes six flexible conductive surfaces 210. In other examples, the apparatus 200 can include more or fewer than six flexible conductive surfaces 210. In some examples, each of the flexible conductive surfaces 210 is substantially the same length. In other examples, the flexible conductive surfaces 210 include different lengths. In some examples, the flexible conductive surfaces 210 are longitudinally spaced along the lead body 202. In some examples, spacing between each of the flexible conductive surfaces 210 is substantially similar. In other examples, spacing between each of the flexible conductive surfaces 210 varies.

In some examples, the at least one flexible conductive surface 210 includes a coil. In some examples, the at least one flexible conductive surface 210 is made of a coiled wire. In some examples, the coil can include an arrangement of single conductors; an arrangement of multistranded conductors, and/or a variety of deposited thin film conductive elements, to name a few. In some examples, the coil of the at least one flexible conductive surface 210 envelopes the circumference of the lead body 202. In some examples, the at least one flexible conductive surface 210 including a coil includes a benefit of increasing the geometric surface area relative to, for instance, a flat surface.

Referring to FIG. 3, an apparatus 300 is configured for at least partial insertion in a living body. In some examples, the apparatus 300 is a stimulation lead for selective attachment to a stimulation device, such as, for instance, a microstimulator. Although described primarily herein with respect to stimulation leads, it should be understood that, in other examples, the apparatus can include other at least partially implantable devices.

In some examples, the apparatus 300 includes an elongate lead body 302 including a proximal lead end 302A and a distal lead end 302B. In some examples, at least one connector 304 is disposed proximate the proximal lead end 302A. In some examples, the at least one connector 304 is configured to electrically couple to the stimulation device. In some examples, a flexible conductive surface 310 is disposed at least partially around the lead body 302 proximate the distal lead end 302B. In some examples, the flexible conductive surface 310 is disposed completely around the lead body 302. The apparatus 300 further includes, in some examples, at least one conductor 306 extending within the lead body 302 from the at least one connector 304 to the flexible conductive surface 310. In some examples, the at least one conductor 306 extends within a lumen 303 of the lead body 302.

In some examples, the flexible conductive surface 310 includes a mesh. In some examples, the flexible conductive surface 310 is made of a metal mesh that envelopes the circumference of the lead body 302. In some embodiments, the mesh of the flexible conductive surface 310 can include a ‘rough’ surface that increases the geometric surface area of the flexible conductive surface 310. In some instances, this increased geometric surface area can reduce the resistance while increasing the reactance of the effective electrode of the flexible conductive surface 310. By doing so, in some examples, the voltage to generate a specific current is reduced throughout the stimulation portion of the waveform, which can save battery power. In some examples, the mesh can include an arrangement of single cross-hatched, braided, or otherwise disposed or applied conductors; an arrangement of multistranded cross-hatched, braided, or otherwise disposed or applied conductors, and/or a variety of deposited thin film conductive elements, to name a few. In other examples, the flexible conductive surface can include a coil, for instance, similar to the at least one flexible conductive surface 210 described herein. In some examples, the coil can include an arrangement of single conductors; an arrangement of multistranded conductors, and/or a variety of deposited thin film conductive elements, to name a few. In some examples, the apparatus 300 includes one relatively long flexible conductor per lead body 302. In some examples, the flexible conductive surface 310 includes a length between 1 cm and 20 cm along the lead body 302. In some examples, this has the advantage of relatively simple manufacture as well as simple programming. Additionally, in some examples, when programmed with a single polarity, this unbroken isopotential surface can reduce the undulating field that occurs when separated contacts are used, such as found on traditional SCS-type leads that have spaced-apart contacts, as seen in FIGS. 4 and 5. FIG. 4 shows potential at various distances from a stimulation lead similar to the apparatus 300 having a single continuous flexible conductive surface that is 6 cm in length. FIG. 5 comparatively shows potential at various distances from a spinal cord stimulation lead having 6 mm contacts with 9 mm spacing. It can be seen that closer to the stimulation lead (for instance, at 2-mm and 4-mm distances), the potential of the single continuous flexible conductive surface lead (FIG. 4) is smoother than the potential of the spinal cord stimulation lead (FIG. 5). The smoother potential near the single continuous flexible conductive surface lead can reduce the likelihood that close neural structures are preferentially activated compared to further neural structures, ideally resulting in a broader area of activation.

Referring to FIG. 6, an apparatus 600 is configured for at least partial insertion in a living body. In some examples, the apparatus 600 is a stimulation lead for selective attachment to a stimulation device, such as, for instance, a microstimulator. Although described primarily herein with respect to stimulation leads, it should be understood that, in other examples, the apparatus can include other at least partially implantable devices.

In some examples, the apparatus 600 includes an elongate lead body 602 including a proximal lead end 602A′, 602A″ and a distal lead end 602B. In some examples, at least one connector 604′ is disposed proximate the proximal lead end 602A′. In some examples, the at least one connector 604′ includes a plug-like connector for engagement with the stimulation device. In other examples, the connector 604″ includes one or more contacts 605″ disposed in-line longitudinally along the lead body 602 proximate the proximal lead end 602A″ of the lead body 602. In some examples, the at least one connector 604′, 604″ is configured to electrically couple to the stimulation device. In some examples, a plurality of flexible conductive surfaces 610 is disposed at least partially around the lead body 602 proximate the distal lead end 602B. In some examples, the plurality of flexible conductive surfaces 610 is disposed completely around the lead body 602. The apparatus 600 further includes, in some examples, at least one conductor 606 extending within the lead body 602 from the at least one connector 604′, 604″ to the plurality of flexible conductive surfaces 610. In some examples, the at least one conductor 606 extends within a lumen 603 of the lead body 602.

In some examples, the apparatus 600 includes at least three flexible conductive surfaces including a center flexible conductive surface 610A including a first length, a distal flexible conductive surface 610B disposed distally on the elongate lead body 602 from the center flexible conductive surface 610A and including a second length, and a proximal flexible conductive surface 610C disposed proximally on the elongate lead body 602 from the center flexible conductive surface 610A and including a third length. In some examples, the second and third lengths of the being shorter than the first length. In some examples, the at least three flexible conductive surfaces 610A, 610B, 610C are longitudinally spaced along the elongate lead body 602 from one another. In some examples, the second length is substantially equal to the third length. In some examples, the first length is about 12-16 mm and the second length and the third length are each about 7-11 mm. In some examples, the flexible conductive surfaces 610 are longitudinally spaced along the lead body 602. In some examples, spacing between each of the flexible conductive surfaces 610 is substantially similar. In other examples, spacing between each of the flexible conductive surfaces 610 varies.

In some examples, the flexible conductive surfaces 610 have different lengths along the lead body 602. In the example shown in FIG. 6, the apparatus 600 includes seven flexible conductive surfaces 610, with the center flexible conductive surface 610A; three distal flexible conductive surfaces 610B, 610D, 610F disposed distally from the center conductive surface 610A; and three proximal flexible conductive surfaces 610C, 610E, 610G disposed proximally from the center conductive surface 610A, with the length of the center flexible conductive surface 610A being the longest and the lengths of the three distal flexible conductive surfaces 610B, 610D, 610F and the three proximal flexible conductive surfaces 610C, 610E, 610G getting shorter the farther from the center flexible conductive surface 610A they are. In some examples, a symmetrical pattern is used in which the largest flexible conductive surface 610A is positioned at the center of the contact array, for instance, approximately 12-16 mm in length; the next largest flexible conductive surfaces 610B, 610C flank the center flexible conductive surface 610A, one to each side and are longer, for instance, approximately 7-11 mm in length; the next smallest flexible conductive surfaces 610 D, 610E flank those outer contacts 610B, 610C, and are shorter in length than the outer contacts 610B, 610C; and so on. In some examples, this decreasing length-from-center pattern is continued for the desired full length of the conductor array along the lead body 602, for instance, approximately 6-20 cm in total.

In some examples, this decreasing length-from-center pattern is done to have the current density delivered from the lead be grossly-but-evenly distributed along the array length when connected to a simple single source (voltage or current) stimulation system. This allows for redistribution of current density “hot spots,” which occur near the edge of a single conductive surface, as seen in FIG. 7. If the flexible conductive surface is very long (for instance, the flexible conductive surface 310 of the lead body 302 of FIG. 7), then the resistive impedance is relatively low, and, with all the surface current leaving the edge of the contact, current density 311 will be relatively high toward the edges and relatively low therebetween. In some embodiments, the different length electrodes (for instance, the flexible conductive surfaces 610 of the lead body 602 of FIG. 7) will have different impedances and lead to more evenly distributed current density 611 along the length of the flexible conductive surfaces 610. This means that, for a fixed applied current or potential to all the flexible conductors, more of the current will be delivered from the center of the conductor array due to the lower impedance of the more central, longer contacts. This can reduce the only-at-the edge “hot spots” that might preferentially recruit Adelta or C fibers and thus limit the amount of current that can be comfortably delivered in PNFS. Since the goal in PNFS is to stimulate innocuous mechanoreceptor fibers (typically large Abeta fibers), having a broad, far-ranging mildly-changing-over-space electric field is considered advantageous.

In some examples, the apparatus 600 can include more or fewer than seven flexible conductive surfaces 610. In some examples, the apparatus 600 can include flexible conductive surfaces 610 of various lengths tailored to the particular application for which the apparatus 600 is being used. As such, it is contemplated in various examples, that the flexible conductive surfaces 610 can include any combination of lengths desired for peripheral nerve stimulation.

In some examples, each of the flexible conductive surfaces 610 includes a mesh. In some examples, each of the flexible conductive surfaces 610 is made of a metal mesh that envelopes the circumference of the lead body 602. In some embodiments, the mesh of each of the flexible conductive surfaces 610 can include a ‘rough’ surface that increases the geometric surface area of each of flexible conductive surfaces 610. In some instances, this increased geometric surface area can reduce the resistance while increasing the reactance of the effective electrode of each of the flexible conductive surfaces 610. By doing so, in some examples, the voltage to generate a specific current is reduced throughout the stimulation portion of the waveform, which can save battery power. In some examples, the mesh can include an arrangement of single crosshatched, braided, or otherwise disposed or applied conductors; an arrangement of multistranded crosshatched, braided, or otherwise disposed or applied conductors, and/or a variety of deposited thin film conductive elements, to name a few. In other examples, each of the flexible conductive surfaces can include a coil, for instance, similar to the at least one flexible conductive surface 210 described herein. In some examples, the coil can include an arrangement of single conductors; an arrangement of multistranded conductors, and/or a variety of deposited thin film conductive elements, to name a few.

Referring to FIG. 8, in some examples, a lead body 802 (which can be used in any of the apparatuses 100, 200, 300, 600 described herein) includes multiple lumens 803, 807. In some examples, the lead body 802 includes two or more conductors, wherein one of the conductors is disposed within a first lumen 807 of the lead body 802 and another of the conductors is disposed within a second lumen 807 of the lead body 802. In some examples, the lead body 802 includes multiple inner lumens 807 which allow multiple conductors to traverse the lead body 802 to their respective flexible conductive surfaces without abrasion against other conductors. In some examples, the lead body 802 includes a stylet lumen 803 configured to accept a stylet within the stylet lumen 803. In some examples, the lead body 802 includes a central lumen 803 to allow for a stylet to be passed through the lead body 802, which can be used to stiffen and/or curve the lead body 802, for instance, for tortuous or obstructed tissue pathways and/or to curve around tissue planes. In some examples, the lead body 802 including multiple lumens 803, 807 allows for improved handling and/or maneuverability of the lead body 802.

Referring to FIGS. 9A-9C, in some examples, stimulation systems 900A, 900B, 900C are shown in some exemplary implanted locations. It should be understood that these implant locations are merely exemplary and that it is contemplated that the stimulation systems 940A, 940B, 940C can be implanted in various other locations of the body that are not specifically shown herein. In some examples, one or more stimulation leads 900A, 900B, 900C with flexible conductive surfaces (similar to any of the apparatuses 100, 200, 300, 600 described herein) are connected to a microstimulator 950A, 950B, 950C. In some examples, the microstimulators 950A, 950B, 950C are present on the same body segment as the respective one or more stimulation leads 900A, 900B, 900C. In this way, by not traversing a joint with the stimulation leads 900A, 900B, 900C, the chances of any one or more of lead damage, lead dislodgment, lead migration, skin erosion, lead-stimulator uncoupling, and lead fatigue are decreased. Some examples of the body segments include: a thigh 10 (FIG. 9A), a calf/shin, a forearm, an upper arm 20 (FIG. 9B), a neck 30 (FIG. 9C), a head, a foot, a hand, or the like, to name a few. In each segment 10, 20, 30, the stimulation system 940A, 940B, 940C includes stimulation leads 900A, 900B, 900C that are of appropriate length to allow for placement within or nearby the therapy target, some looping to inhibit tension from creating migration of the stimulation lead 900A, 900B, 900C, and/or connection to the microstimulator 950A, 950B, 950C, all implanted within that body segment 10, 20, 30.

It is noted that, while the present figures portray example leads with flexible conductive surfaces having a greater diameter than the respective lead bodies, in other examples, it is contemplated that the flexible conductive surfaces have substantially the same diameter as the respective lead bodies, making the leads isodiametric.

In some examples, the lead (for instance, any of the apparatuses 100, 200, 300, 600, 900A, 900B, 900C) has a relative small diameter, ranging between about 0.1 mm and about 1 mm. In some examples, this allows for better ability to place and position the lead over areas with thin regions of soft tissue, such as the skull, for instance, improving cosmesis as well as reducing the likelihood of erosion. In some embodiments, the lead body 102, 202, 302, 602 is made of a biocompatible polymer, which is flexible and durable within the body. In some examples, this can be advantageous for extremities, which are typically in motion and undergo shape changes and make frequent contact with the outside world during activities of daily living.

In various examples described herein, it is contemplated that peripheral nerves may be directly targeted to mitigate chronic pain of limbs, for instance. The various flexible conductive surfaces 110, 210, 310, 610 described herein allow for increased flexibility of the respective lead bodies 102, 202, 302, 602, allowing for better body conformance, increased comfort, decreased skin erosion, and the like. Additionally, the various flexible conductive surfaces 110, 210, 310, 610 described herein allow for increased contact, leading to more effective and efficient use of power, which, in some examples, can be advantageous due to the desired smaller size of components. In some examples, the various flexible conductive surfaces 110, 210, 310, 610 described herein allow for stimulation of a relatively wide area with relatively low power needed to do so.

The present inventor has recognized various advantages of the subject matter described herein. For instance, in some examples, the apparatuses, systems, and methods described herein can be used to better provide PNFS using one or more flexible conductive surfaces. In various examples, the apparatuses, systems, and methods described herein are considered advantageous in that they allow for generation of a broad field to provide better PNFS. Additionally, in various examples, the apparatuses, systems, and methods described herein include PNFS apparatuses, systems, and methods sized, shaped, or otherwise configured for placement in patient extremities or other body segments. While various advantages of the example apparatuses, systems, and methods are listed herein, this list is not considered to be complete, as further advantages may become apparent from the description and figures presented herein.

Although the subject matter of the present patent application has been described with reference to various examples, workers skilled in the art will recognize that changes can be made in form and detail without departing from the scope of the subject matter recited in the below claims.

The above Detailed Description includes references to the accompanying drawings, which form a part of the Detailed Description. The drawings show, by way of illustration, specific examples in which the present apparatuses and methods can be practiced. These embodiments are also referred to herein as “examples.”

The above Detailed Description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more elements thereof) can be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. Also, various features or elements can be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter can lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

In this document, the terms “a” or “an” are used to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “about” and “approximately” or similar are used to refer to an amount that is nearly, almost, or in the vicinity of being equal to a stated amount.

In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, an apparatus or method that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 

1. An apparatus configured for at least partial insertion in a living body, the apparatus comprising: an elongate lead body including a proximal lead end and a distal lead end; at least one connector disposed proximate the proximal lead end; at least one flexible conductive surface disposed at least partially around the lead body proximate the distal lead end; and at least one conductor extending within the lead body from the at least one connector to the at least one flexible conductive surface.
 2. The apparatus of claim 1, wherein the at least one flexible conductive surface includes a mesh.
 3. The apparatus of claim 1, wherein the at least one flexible conductive surface includes a coil.
 4. The apparatus of claim 1, wherein the at least one flexible conductive surface is disposed completely around the lead body.
 5. The apparatus of claim 1, wherein the at least one flexible conductive surface includes a length between 1 cm and 20 cm.
 6. The apparatus of claim 1, wherein the at least one flexible conductive surface includes two or more flexible conductive surfaces.
 7. The apparatus of claim 6, wherein the two or more flexible conductive surfaces includes at least three flexible conductive surfaces, wherein: a center flexible conductive surface includes a first length; a distal flexible conductive surface disposed distally on the elongate lead body from the center flexible conductive surface and including a second length; and a proximal flexible conductive surface disposed proximally on the elongate lead body from the center flexible conductive surface and including a third length, the second and third lengths being shorter than the first length.
 8. The apparatus of claim 7, wherein the at least three flexible conductive surfaces are longitudinally spaced along the elongate lead body from one another.
 9. The apparatus of claim 7, wherein the second length is substantially equal to the third length.
 10. The apparatus of claim 7, wherein the first length is 12-16 mm and the second length and the third length are each 7-11 mm.
 11. The apparatus of claim 1, wherein the at least one conductor extends within a lumen of the lead body.
 12. The apparatus of claim 1, wherein the at least one conductor includes two or more conductors, wherein one of the conductors is disposed within a first lumen of the lead body and another of the conductors is disposed within a second lumen of the lead body.
 13. The apparatus of claim 12, wherein the lead body includes a stylet lumen configured to accept a stylet within the stylet lumen.
 14. An apparatus configured for at least partial insertion in a living body, the apparatus comprising: an elongate lead body including a proximal lead end, a distal lead end, and a lumen within the lead body; a connector disposed proximate the proximal lead end; a flexible conductive surface disposed at least partially around the lead body proximate the distal lead end; and a conductor extending within the lumen, the conductor extending from the connector to the flexible conductive surface.
 15. The apparatus of claim 14, wherein the flexible conductive surface includes a mesh.
 16. The apparatus of claim 14, wherein the flexible conductive surface includes a coil.
 17. The apparatus of claim 14, comprising at least a second flexible conductive surface disposed at least partially around the lead body proximate the distal lead end.
 18. An apparatus configured for at least partial insertion in a living body, the apparatus comprising: an elongate lead body including a proximal lead end, a distal lead end, and at least one lumen within the lead body; at least one connector disposed proximate the proximal lead end; at least one flexible conductive surface disposed around the lead body proximate the distal lead end; at least one conductor extending within the at least one lumen, the at least one conductor extending from the at least one connector to the at least one flexible conductive surface; and a stylet lumen disposed within the lead body, the stylet lumen configured to accept a stylet within the stylet lumen.
 19. The apparatus of claim 18, wherein the flexible conductive surface includes a mesh.
 20. The apparatus of claim 18, wherein the flexible conductive surface includes a coil. 